Well we have to be careful, don't we? [ as soon as she says it, she realizes that wasn't the right choice of words. not with Jack, who seems entirely focused on the parts about these particular powers that she wouldn't let herself get too attached to. the... using it for fun, to play and goof off. as much as she liked to hope that that's all her powers would be used for in the future, she knew she couldn't let herself get distracted by that mindset. not when said powers almost cost her sister her life life, twice.

she pushes off her skates with an easy grace, hands folding behind her back ]

I just mean that our powers can be fun, and be used to bring fun, but they can also be dangerous. Some people tend to ignore the former when presented with a kind of magic they don't understand. Or any magic at all, I suppose.